Class: ActiveRecord::Materialized::SchemaVerifier

Inherits:
Object
  • Object
show all
Defined in:
lib/activerecord/materialized/schema_verifier.rb

Overview

Raises when a provisioned cache table no longer matches the columns its source relation projects (drift); never alters the table or rebuilds data.

Defined Under Namespace

Classes: SchemaDriftError

Instance Method Summary collapse

Constructor Details

#initialize(view_class) ⇒ SchemaVerifier

Returns a new instance of SchemaVerifier.



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# File 'lib/activerecord/materialized/schema_verifier.rb', line 11

def initialize(view_class)
  @view_class = view_class
end

Instance Method Details

#drifted? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/activerecord/materialized/schema_verifier.rb', line 26

def drifted?
  verify!
  false
rescue SchemaDriftError
  true
end

#verify! ⇒ Object

An unprovisioned cache table is absent, not drifted, so this is a no-op.



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# File 'lib/activerecord/materialized/schema_verifier.rb', line 16

def verify!
  return unless @view_class.table_exists?

  missing = expected_columns - actual_columns
  extra = actual_columns - expected_columns
  return if missing.empty? && extra.empty?

  Kernel.raise SchemaDriftError, drift_message(missing, extra)
end